Anti-theft detector and alarm systems for vehicles

ABSTRACT

Alarm apparatus for use on motor vehicles includes a detector having a self-leveling mount and a relatively heavy, generally spherical contact member which is adjustably suspended from a cable and normally spaced within an outer concentric contact member so that when the suspended contact member moves to and fro in a pendulum action, in response to unauthorized vehicle movement, it will make contact with the outer contact member. An alarm system for the detector is activated by the contact members interconnected so as to regulate the actuation of an alarm element. One alarm system carried by the vehicle applies the vehicle battery power to the vehicle horn, and in the event the vehicle battery fails power from an auxiliary battery is used to actuate a secondary alarm element. Another alarm system is a remote location from the vehicle, such as, in the home may be cable-connected to the detector to give an audible signal in the home when the vehicle is moved.

United States Patent Eversull [54] ANTI-THEFT DETECTOR AND ALARM SYSTEMSFOR VEHICLES Richard F. Eversull, 5009 Ogallala Place, Cheyenne, Wyo.82001 [22] Filed: May 27,1970

[21] Appl.No.: 41,020

[72] Inventor:

[52] U.S.Cl

....340/65, 200/6152 ..B60r 25/10 Field of Search ..340/52 H, 63, 64,65;

ZOO/61.45, 61.52; 307/10 [56] References Cited UNITED STATES PATENTS2,947,830 8/1960 Goss ..340/65 X FOREIGN PATENTS OR APPLICATIONS 118,0171/1944 Australia ..340/65 [151 3,659,265 [451 Apr. 25, 1972 PrimaryExaminer-Alvin H. Waring Attorney-Reilly and Lewis [57] ABSTRACT Alarmapparatus for use on motor vehicles includes a detector having aself-leveling mount and a relatively heavy, generally spherical contactmember which is adjustably suspended from a cable and normally spacedwithin an outer concentric contact member so that when the suspendedcontact member moves to and fro in a pendulum action, in response tounauthorized vehicle movement, it will make contact with the outercontact member. An alarm system for the detector is activated by thecontact members interconnected so as to regulate the actuation of analarm element. One alarm system carried by the vehicle applies thevehicle battery power to the vehicle horn, and in the event the vehiclebattery fails power from an auxiliary battery is used to actuate asecondary alarm element. Another alarm system is a remote location fromthe vehicle, such as, in the home may be cable-connected to the detectorto give an audible signal in the home when the vehicle is moved.

6 Claims, 7 Drawing Figures PATENTEDAPR 25 I972 sum 1 0? 2 l N VENTORRICHARD E EVERSULL Iii ATTORNEYS 'PATENTEDAPR 25 m2 SHEET 2 OF 2 AUDIOGENERATOR ANTI-THEFT DETECTOR AND ALARM SYSTEMS FOR VEHICLES Thisinvention in general relates to alarm apparatus and more particularly tonovel and improved anti-theft detector and alarm systems utilizing thedetector which respond to unauthorized movement of a motor vehicle or alike movable object.

A variety of anti-theft systems have heretofore been provided to protectagainst unauthorized use of a motor vehicle. In many instances suchdevices have been responsive to the unauthorized use of an electricalload on the vehicle, such as, the starter, a light, or the like. Inother instances the alarm detectors have been responsive either totilting or other movement of the vehicle.

Accordingly, it is an object of this invention to provide a novel andimproved anti-theft detector which is readily attachable to a motorvehicle and is so constructed and arranged as to be highly sensitive tounauthorized movement of the vehicle or any portion thereof.

Another object of this invention is to provide a highly sensitive andreliable detector for use on motor vehicles utilizing pendulumprinciples to interrupt and complete an alarm circuit.

Yet another object of this invention is to provide an improvedmovement-responsive detector including a self-leveling mount and wherethe detector may be set to difierent degrees of sensitivity, asrequired.

A further object of this invention is to provide novel and improvedalarm systems which are readily adapted for use in association withconventional motor vehicles.

A further object of this invention is to provide novel and improvedalarm systems locatable in the vehicle or at a remote location from thevehicle which are responsive to the momentary contact of a pair ofcontact members.

Yet a further object of this invention is to provide novel and improvedalarm apparatus for 'a motor vehicle including movement-responsivedetector on the vehicle and a primary alarm circuit responsive to thedetector to actuate an alarm element on the vehicle and a secondaryalarm circuit responsive to a failure of the primary alarm circuit toactivate yet a second alarm element on the vehicle.

In accordance with the present invention there has been devised adetector including a self-leveling elongated housing in which a contactmember is suspended for free swinging movement in normally spacedrelation to an outer concentric contact member. The contact members areconnected to external terminals which in turn are connected to an alarmcircuit system for selective actuation of an alarm element. Preferably,suspended contact member is in the form of a weighted, conductive ballsuspended from a cable within a housing, and the outer contact member isin the form of a ring disposed in the wall of the housing, contact beingmade between the two members when the ball swings from the verticalunder the forces of gravity when the vehicle or any portion thereof ismoved. An alarm system on the vehicle may employ the vehicle battery andhorn to produce an audible sound and also may include a secondarycircuit powered by an auxiliary battery operable to actuate an audiogenerator and a radio broadcast receiver. In the alternative, a remotealarm system in the home is cable-connected to the detector to producean alarm signal remote from the vehicle.

Other objects, advantages and capabilities of the present invention willbecome more apparent as the description proceeds taken in conjunctionwith the accompanying drawings, in which:

FIG. 1 is a side elevation view of the detector and a detector and alarmcircuit housing adapted to mount on a vehicle.

FIG. 2 is a front elevation view of the detector and housing shown inFIG. 1.

FIG. 3 is an enlarged vertical sectional view through the detector shownin FIG. 1.

FIG. 4 is a top plan view taken along lines 4-4 of FIG. 3 looking downinto the intermediate housing.

FIG. 5 is an enlarged top plan view of the mounting base for thedetector shown in FIGS. 1-4.

FIG. 6 is a schematic circuit diagram of a vehicle-mounted,self-contained alarm system usable with the detector shown in FIGS. 1-5;and

FIG. 7 is a schematic circuit diagram of a remotely located alarm systemusable with the detector shown in FIGS. 1-5.

Referring now to the drawings, the preferred form of alarm apparatusshown in FIGS. 1-5 is adapted for use with a motor vehicle and isbroadly comprised of a detector 12 which extends downwardly from thelower end of an alarm housing 13 through a bottom opening 13a. Thehousing 13 is attachable to a motor vehicle by any suitable means suchas a bracket on the housing, with fasteners or the like, not shown, sothat the detector 12 will in effect be carried from the vehicle andrespond to movement thereof.

Broadly stated, detector 12 is in the form of a normallyopen,movement-responsive electric switch which is closed when the object onwhich it is mounted is moved, and detector 12 is connected into thecircuit of an alarm system which selectively regulates power from apower source to an alarm element. The housing 13 preferably is arrangedto contain alarm circuits, described hereinafter with reference to FIG.6, which may for example be located on an upper shelf 14, and thehousing 13 is of a tamper-proof construction with a hinged front door 15to be locked to protect the detector 12 and the contained alarm circuitsof the alarm system and yet provide ready access thereto.

The detector 12 shown comprises an elongated tubular housing or tube 17,an intermediate housing 18 surmounted on the tubular housing 17, and amount portion 19 surmounted on the intermediate housing above thetubular housing 17. The detector 12 is arranged to be swinginglysupported so that the tubular housing 17 and its contents at all timeswill be oriented along a vertical axis and maintain a vertical attitudeindependently of the inclination of the vehicle. To this end there isprovided a mounting base 21 disposed on an intermediate shelf 22centrally of the housing 13. Base 21 has a concave, generallysemi-spherical upper support surface 23 and a radial slot 24 extendingthrough its forward side which opens toward the access door 15 tofacilitate easy removal and replacement of the detector 12 from housing13. The mount portion 19 at the upper end of the detector 12 includes agenerally spherical or rounded head 19a and a narrowed neck 19b whichwidens into a flat base plate attaching to the top of the intermediatehousing 18. Base plate 190 may be removably attached to the housing 18using bolts or the like. The rounded surfaces of the mounting base 21and the head portion 19 are complementary and slide freely against oneanother and are formed as smooth surface areas to reduce friction. Tothis end the surfaces of the head portion 19a may be an ultra-hardTeflon-coated plastic and the mounting base 21 Teflon-coated polishedsteel.

When the detector 12 is in an operative position on the mounting basethe neck portion 19b is positioned in the slot 24 and the complementaryrounded surfaces of head portion 190 and support surface 23 are inengagement with one another. The spherical head 19a is centered on thevertical axis of the tubular housing and the force of gravity will causethe tubular housing 17 to move to a vertical orientation since it isfree to swing about its upper end. Additional weight in the form ofsolid shot or lead 26 is loaded into the bottom of the tubular housing17 to insure the self-leveling thereof. As shown in FIG. 3 an invertedU-shaped partition 27 is nested in the bottom of the housing 17 and isfixedly secured thereto. The weight 26 is held in the U-shaped housing27 by a closure plate 28 press-fitted in the open underside of partition27, and a flanged removable cap 29 is threaded into the lower open endof the housing 27.

A clamp mechanism is provided to grip the tubular housing 17 and secureit against swinging movement when not in use. This clamp mechanism iscomprised of a hinge 30 attached to the bottom wall of the housing 13adjacent to and rearwardly of the tubular housing 17, and a lowervertical extension 31 of the hinge supports a pair of forwardlyextending, springloaded arcuate gripping arms 32 and 33 yieldinglyengaging opposite sides of the housing 17. Although not shown, the hingeis preferably spring-tensioned to automatically move the entrance awayfrom the detector when the clamp arms are released and release thedetector.

Within the tubular housing 17 there is suspended a solid, generallyspherical contact member 35 preferably made of steel suspended from aconductive cable 36 centered in the tubular housing 17, and an outerconcentric ring-like contact member 37 of a conductive material is alsocentered in the tubular housing concentric with and normally spaced fromthe suspended ball 35 when the suspended ball is elevated from theinactive position shown, as described hereinafter. The inner surface ofthe outer contact ring 37 is inclined outwardly and downwardly toprovide an upwardly convergent circumferentially extending surfacecontact area, and a relatively narrow band or ring portion 38 extendsupwardly from the central portion which inclines outwardly and upwardlyto provide an upwardly divergent and circumferentially extending outersurface contact area which directly contacts ring 37. The suspendedcontact member 35 is in an operative position when its ring portion 38is within ring 37 so that lateral movement of ring 38 produces acontact. The suspended contact member 35 is elevated to its operativeposition by moving shaft 14 inwardly from the position shown to elevatemember 35 and in this position the opposed conductive surface contactareas defined by rings 37 and 38 are directly opposite one another in arelatively close proximity to form an annular air gap or spacetherebetween, making the detector sensitive to the movement of thevehicle in substantially any direction.

The cable 36 is suspended from the inner end of an actuator shaft 41.The mounting arrangement for the shaft is in the intermediate housing 18and includes an inwardly directed tubular extension 42 arrangedtransversely of the top of the tubular housing 17 and through a sidewall of housing 18. The upper end of the cable 36 extends through and isslidable in an outwardly and upwardly tapered aperture 43 in the innerend of the shaft 41 and then fixedly attaches at its upper end to aninternal electric terminal 44 located in the bottom wall of the shafthousing 18. The raising and lowering of the suspended contact member 35will then be carried out by movement of the shaft inwardly into thehousing 18 away from the centered position shown in FIG. 3, during whichcable 36 will slide in aperture 43. In the centered position the taperedaperture 43 is aligned with the axis or center of tubular housing 17.The range of horizontal movement for the shaft is from the outermostposition shown to an innermost position over a range of movementrepresented at A and the corresponding range of vertical movement forthe suspended contact member 35 is over a distance represented at B.

The movement of actuator shaft 45 inwardly into the housing is resistedby the spring-loading of shaft 45. This springloaded arrangementincludes a tension spring 46 on the shaft within housing 18 which isheld under tension between a washer 47 at the end of the shaft justinwardly of the shaft aperture 43 and the inner end of the tubularextension 42. To hold the shaft at one of a plurality of settings, theshaft is provided with a series of spaced notches 48 along its undersidewhich releasably engage the top edge of a laterally projecting latchingand release lever 49 which extends across to cover a lower portion of anaperture in a side plate 51 mounted on the side of the housing 18. Thelever 49 may be resiliently urged upwardly against the shaft 41 by apusher and compression spring, not shown. When the shaft is in theoutermost position shown, the innermost notch relative to the inner endof the shaft engages the latching and release lever 49 and eachsucceeding notch toward the outer end of the shaft provides apreselected amount of inward positioning of the shaft, thereby resultingin elevating the suspended contact member 35 within the tubular housing17 in a series of preselected steps.

To facilitate the centering of the cable 36 in the tubular housing 17for all settings of the actuator shaft 41, the upper end of the cableextends vertically upwardly through a tubular guide 52 mounted in thebottom wall of the intermediate housing 18. The guide 52 has acylindrical lower portion which terminates in an outwardly and upwardlydiverging upper end section having a smooth rounded top edge which mayfor example be polished metal to maintain a free sliding movement of thecable in its vertical movement by shaft 41. In the outermost setting ofthe shaft, as shown, aperture 43 is located directly above the center ofthe guide 52, and the suspended contact member 35 is in its lowermostposition where it rests on a carrier member 53 and at this position thecable 36 is taut. As the shaft 41 is advanced into the housing 18 thecable 36 will ride against guide 52 and elevate the suspended contactmember 35 to gradually decrease the air gap between rings 37 and 38 sothat the detector will be most sensitive at its highest setting and evena very slight movement of member 35 will tend to cause a contact betweensections of the opposed surface areas in response to a movement of thevehicle. A sensitivity gauge 55 is mounted under the outer end of theshaft on the side of the housing 18 and has indicia 56 along each sideof a central curved recess as best shown in FIG. 4 which will indicatethe extent of movement of the shaft into the housing 18 and thereby thesensitivity setting of the detector. In addition, the shaft 41 isprovided with a knob 57 for gripping by the user at its outer end and acircular stop inwardly of the knob 58.

The internal terminal 44 connected to the upper end of cable 39 connectsto an external terminal designated R, mounted in the top of the mountportion 19, through a line or conductor 50. Conductor 50 passes upwardlythrough the top wall of the housing 18 and through the head portion 19a.A releasable connector may be provided between terminal 44 and line 50,as shown, to facilitate ready removal of the top of the housing 18. Theouter contact ring 37 connects through vertical connecting bar 59 to anupper conductive ring 60 in the tubular housing above ring 37. Aresilient contactor 61 is supported from the bottom wall of housing 18and has a curved lower end portion held in engagement with the upperring 60 to make an electric contact therewith and has its upper endconnected to an internal terminal 62 on the bottom wall of the housing18. As shown in FIG. 3 the tubular housing 17 threads into an opening inthe bottom of housing 18. A line or conductor 63 connects between aninternal terminal 62 and an external terminal L adjacent externalterminal R in the head portion. Again a releasable connector may be usedat the inner end of line 63 as shown to releasably connect it toterminal 62 to facilitate removal of the head portion 19 and top wall ofhousing 18.

Summarizing then, the circuit through the detector 12, beginning withexternal terminal R, is through line 50, internal terminal 44, cable 36,and ball-shaped contact member 35 including ring portion 38. With anouter surface area section of ring 38 contacting an inner surfacesection of outer ring 37 in response to a movement of member 35, thecircuit is completed through the detector via contact ring 37, bar 59,ring 60, connector 61, internal terminal 62 and line 63 to the externalterminal L. As shown in FIG. 1 the external terminals L and R areinterconnected by conductors 64 and 65 to the alarm circuits andelements represented in dashed lines 66 which are shown as mounted inthe upper portion of housing 13.

An alarm system herein referred to as the vehicle-mounted alarm systemis represented as being contained in blocks 66 in the vehicle-mountedhousing in FIG. 1 and is represented in a dashed line block 66 in theschematic diagram of FIG. 6. This alarm system includes a primary alarmcircuit arranged to connect the power from the vehicle DC battery B1 tothe vehicle horn H. The detector 12 described fully in FIGS. 1-5 isrepresented schematically in FIG. 6 as an electric switch with externalterminals L and R being connected and disconnected by the movement of amovable contact arm. In this alarm circuit there is provided an on-offcontrol switch 71 preferably mounted in housing 13 having contacts 71acontrolling the power from the vehicle battery B1 to the coil of a holdrelay 72 via a fuse F l and a current limiting resistor 73. Hold relay72 has three sets of contacts represented at 72a, 72b and 72c. Each setof the contacts of relay 72, as well as those of the relays hereinafterdescribed, has an associated third contact shown which is a dummycontact for engaging the movable contact arm when it is moved to the OFFposition but each set of contacts herein referred to are those whichcome together to complete and separate to interrupt the circuit in whichthey are connected.

A vehicle horn relay 75 has normally-open contacts 75a which when closedconnect the battery B1 directly to the horn H upon the energization ofrelay 75. One side of the coil of relay 75 is connected to the batteryB1 and the other side of the coil to a first grounding circuit whichincludes terminal block TB-l, the detector 12, a delay-on timer T1 andcontacts 72a, to ground. Once the on-off control switch 71 is in the ONposition and after the delay-on timer T1 has run, the closure of thecontacts in the detector 12 functions to complete the first groundingcircuit for the coil of relay 75 and this in turn closes contacts 75a toactuate the horn H. Tlmer T1 is preferably mechanically set and has anon-delay, adjustable from to minutes, to prevent activation of thesystem until after the driver has set the detector and control circuitsand left the vehicle.

A second grounding circuit for the coil of the relay 75 includes ahold-on timer T2 having three terminals 76, 77 and 78. Terminal 76 isconnected to the ground side of the coil of relay 75. Terminal 77connects to the battery B1 via fuse F1 and terminal 78 is connected toground. The hold-on timer T2 shown has a thermal-operated automaticresetting time-on switch 81 with a relay 82. The coil of relay 82 isconnected between terminals 76 and 77 via switch 81 with thenormallyopen contacts 82a of the relay 82 being connected betweenterminals 76 and 78. With this arrangement, when the detector 12 isactuated, the coil of relay 75 is momentarily grounded by the firstgrounding circuit. The coil of relay 82 is simultaneously energized withthe initial energization of relay 75 to hold the ground for relay 75 fora predetermined time interval, such as, for 3 to 5 seconds via terminals76 and 78. After this interval thermal switch 81 opens to de-energizerelay 82 to remove ground for the coil of relay 82 and stop the born.The horn sounding will start again for the same interval for eachsubsequent actuating movement of the detector.

A secondary or auxiliary alarm system, a portion of which is alsoincluded in housing 13, takes over if the vehicle battery Bl fails or isdisconnected. This system is powered by an auxiliary hot-shot typebattery B2 carried preferably in the trunk of the vehicle which, broadlystated, provides a control signal to actuate an audio signal generator84 and a broadcast radio receiver 85 and connects the output of thesignal generator 84 to the input of an audio amplifier stage of avehicle broadcast radio receiver 85.

The audio generator 84 is preferably a conventional solidstate, DCpowered unit operating at audio frequencies. A police siren or anycombination of tones are generated by generator 84 and these tones areamplified in the broadcast receiver 85 and reproduced as audible soundthrough the radio speaker in the broadcast radio receiver 85 to alertsomeone as to the unauthorized use of the vehicle. When the secondaryalarm system takes over, the coil of hold relay 72 is de-energized withits contacts returning to the OFF position shown. This also mutes thedetector 12 since one side of its circuit is completed to ground viacontacts 72a. The power from the secondary battery B2 is applied througha fuse F2 and contacts 71b to the input side of an on-hold, timer T3 andfrom there through the relay contacts 72b to the input of the audiogenerator 84. Timer T3 is settable to maintain the power for apredetermined period, as for example 0 to minutes, and then theauxiliary power from battery B2 to the generator 84 and other loaddevices hereinafter described is interrupted.

The output of the audio generator 84 is applied through a shieldedconductor 87, through contacts 72c, through shielded conductor 88 andthrough the contacts 89a of an input relay 89 into the broadcast radioreceiver 85. The power from the auxiliary battery B2, through closedcontacts 72b, is also applied through diode 93 to the input of thebroadcast radio receiver and to the coil of relay 89 so that theythereby are simultaneously energized when the energization of the audiogenerator 84 takes place. The blocking diode 93 is connected between theinput of the broadcast radio receiver 85 and the relay coil 89 so thatthe broadcast radio receiver 85 is turned on for normal operation bypower from primary battery B1 indicated at a terminal which is appliedto the receiver 85 through the regular broadcast radio on-off switch 91.With this arrangement relay 89 would not be energized during the normaloperation of the radio receiver 85 until such time as the primarybattery B1 fails and the secondary alarm system takes effect.

The operation of the detector 12 and the vehicle-mounted control systemshown in FIG. 6 will now be summarized. Upon leaving the vehicle theclamp arms 32 and 33 are released and the sensitivity of detector 12 isset by moving the actuator shaft 41 into the housing to elevate theball-shaped contact member 35 into the operative position. The delay-ontimer T1 is set to allow sufficient time for the driver to get out ofthe vehicle without triggering the alarm and control switch 71 is turnedto the ON position. The door 15 is then closed and locked. Once timer T1has run, movement of the vehicle will bring the contact member in thedetector together thereby completing the grounding circuit for relay 75which causes it to turn on. Timer T2 holds the horn H on for apredetermined interval by providing a secondary ground for relay 75after the primary ground via detector 12 opens. This sequence repeats aslong as the vehicle movement continues since there will be repeatedengagements between the contact members in the detector 12.

In the event that this primary alarm system is rendered ineffective,such as if the vehicle battery is disconnected, the hold relay 72 turnsto the OFF position and triggers the secondary alarm system. Theauxiliary battery B2 is then connected via timer T3 to turn the audiogenerator and broadcast radio receiver on. The timer T3 holds this alarmcircuit in operation for a predetermined period and then opens thiscircuit to shut off the alarm.

A extra-vehicular alarm system adapted to be located remote from thevehicle and actuated by the detector 12 on the vehicle is shown in FIG.7 and is enclosed in a dashed line block at 95. The detector 12, aterminal block TB-2 and a solenoid relay switch SR are located on thevehicle represented in dashed lines again at 67. The remotely locatedalarm circuits 95 are connected by cables comprised of a plurality oflines between circuits 95 and the vehicle 67 represented in dashed linesat 98. This remote alarm system may use available house power (ll0-voltAC power) which is applied to input terminals 101 and 102.

The AC power supplied to input terminals 101 and 102 is stepped down bya transformer 103. An on-off power control switch 104 is connected tothe secondary winding of the transformer 103 to regulate the power tothe alarm element and control circuits. The control switch 104 connectsto one side of the detector 12 via terminal block TB-2, to one side ofthe coil of relay 107, to one of the set of contacts 111a of a solenoidrelay switch SR, to one of the set of contacts 107a of relay 107 and toone of the set of contacts of a momentary detent, reset switch 108. Theother side of the detector 12 returns through one coil 111 of thesolenoid relay switch SR and back to ground through line 113 of thecable 98. The other contact of set 107a connects to the alarm element114 which may be a bell or buzzer. The other contact of set 1110 alsoconnects to the alarm buzzer 114 and the other of the set of contacts ofswitch 108 connects to the ungrounded side of the other coil 115 ofswitch SR.

In the operation of the remote alarm system, when power switch 104 isclosed in the home and the detector contacts close in the vehicle 67,coil 111 is momentarily energized causing closure of contacts 111a toapply the power from the transformer to the alarm bell or buzzer 114.Contacts 111a remain closed upon the momentary energization via thedetector until the second winding 115 is energized. A depression ofreset switch 108 causes contacts 111a to return to the open position tostop the alarm buzzer 114. The hold relay 107 remains energized whilethe system is on and if the coil circuit of relay 107 opens, which couldresult by cutting or disconnecting or severing the cable 98, then thebuzzer or bell 114 is actuated via contacts 107a and remains on untilswitch 104 is turned off. This feature provides additional alarmversatility for the surveillance of vehicles near the home and operatesindependently of the detector 12.

Although the present invention has been described with a certain degreeof particularity, it is understood that the present disclosure has beenmade by way of example and that changes in details of structure may bemade without departing from the spirit thereof.

What is claimed is:

1. Anti-theft detector apparatus for use on a motor vehicle to actuatean alarm element in an alarm circuit, said detector apparatus comprisinga mounting base secured to the vehicle having an upper rounded supportsurface and a radially extending slot,

a tubular housing having a mount portion in its upper end including anarrowed neck portion positioned in said slot and terminating at itsupper end in an enlarged head portion seated on said upper roundedsupport surface for swingingly supporting said tubular housing from saidbase so that the tubular housing maintains a vertical attitudeindependently of the inclination of the vehicle,

a generally spherical contact member suspended from a cable for freeswinging movement in the housing and electrically connnected to anexternal terminal mounted on said head portion, said external terminalbeing connected in said alarm circuit, and

a ring-like contact member concentric with and normally spaced from thesuspended contact member and electrically connected to a second terminalon said head portion, said second terminal connecting in said alarmcircuit, whereby a movement of the vehicle causes the suspended contactmember to move in a pendulum action into engagement with said ring-likecontact member to short-circuit said first and second terminals andthereby complete said alarm circuit to said alarm element.

2. Anti-theft detector apparatus as set forth in claim 1 wherein saidmounting base is enclosed in a vehicle-mounted housing having a bottomopening through which a portion of said tubular housing extends.

3. Anti-theft detector apparatus as set forth in claim 1 including areleasable clamp secured on said vehicle-mounted housing to rigidlysecure the tubular housing against swinging movement when not in use.

4. An anti-theft detector for use on motor vehicles to actuate an alarmelement in an alarm circuit, said detector comprising a housingswingingly supported from the vehicle so as to maintain a verticalattitude independently of the inclination of the vehicle,

a pair of contact members within the housing and connected in the alarmcircuit, said contact members being spaced apart and movable intocontact with one another, one of said contact members being suspendedfor free swinging movement whereby a movement of the vehicle causes'thecontact members to contact one another to complete the alarm circuit,and an actuator shaft extending above and transversely of the top of theelongated housing from which said suspended contact member is supportedfor a free swinging movement in said elongated housing, said actuatorshaft being adjustable laterally of the upper end of said elongatedhousing to move said suspended contact member to a selected elevation insaid housing. 5. An anti-theft detector for use on motor vehicles toactuate an alarm element in an alarm circuit, said detector comprising ahousing swingingly supported from the vehicle so as to maintain avertical attitude independently of the inclination of the vehicle,

a pair of contact members within the housing and connected in the alarmcircuit, said contact members being spaced apart and movable intocontact with one another, one of said contact members being suspendedfor free swinging movement whereby a movement of the vehicle causes thecontact members to contact one another to complete the alarm circuit,and an actuator shaft extending above and transversely of the top of theelongated housing from which said suspended contact member is supportedfor a free swinging movement in said elongated housing, said actuatorshaft being adjustable laterally of the upper end of said elongatedhousing to move said suspended contact member to a selected elevation insaid housing, said suspended contact member being generally spherical inshape and having a ring-shaped section around its center, the outercontact surface area of said ring-shaped section inclining outwardly anddownwardly and the inner associated contact surface area of the othercontact member inclining outwardly and upwardly to decrease the airspace therebetween as said suspended contact member is elevated.

6. Anti-theft alarm apparatus for use on a motor vehicle to actuate analarm element comprising a detector on the vehicle having a set ofnormally open contact members adapted to momentarily close when thevehicle is moved, and

an alarm circuit including means responsive to a momentary engagement ofsaid contact members to actuate said alarm element for a predeterminedtime interval each time said contact members are closed, said vehiclehaving a DC battery and a horn, said horn serving as the alarm elementand being actuated from said vehicle battery, and

a secondary alarm circuit triggered by the disconnecting of said vehiclebattery, said secondary alarm circuit including an auxiliary batteryarranged for connecting the power from said auxiliary battery to anaudio generator having its output coupled to the input of a radiobroadcast receiver.

1. Anti-theft detector apparatus for use on a motor vehicle to actuatean alarm element in an alarm circuit, said detector apparatus comprisinga mounting base secured to the vehicle having an upper rounded supportsurface and a radially extending slot, a tubular housing having a mountportion in its upper end including a narrowed neck portion positioned insaid slot and terminating at its upper end in an enlarged head portionseated on said upper rounded support surface for swingingly supportingsaid tubular housing from said base so that the tubular housingmaintains a vertical attitude independently of the inclination of thevehicle, a generally spherical contact member suspended from a cable forfree swinging movement in the housing and electrically connnected to anexternal terminal mounted on said head portion, said external terminalbeing connected in said alarm circuit, and a ring-like contact memberconcentric with and normally spaced from the suspended contact memberand electrically connected to a second terminal on said head portion,said second terminal connecting in said alarm circuit, whereby amovement of the vehicle causes the suspended contact member to move in apendulum action into engagement with said ring-like contact member toshort-circuit said first and second terminals and thereby complete saidalarm circuit to said alarm element.
 2. Anti-theft detector apparatus asset forth in claim 1 wherein said mounting base is enclosed in avehicle-mounted housing having a bottom opening through which a portionof said tubular housing extends.
 3. Anti-theft detector apparatus as setforth in claim 1 including a releasable clamp secured on saidvehicle-mounted housing to rigidly secure the tubular housing againstswinging movement when not in use.
 4. An anti-theft detector for use onmotor vehicles to actuate an alarm element in an alarm circuit, saiddetector comprising a housing swingingly supported from the vehicle soas to maintain a vertical attitude independently of the inclination ofthe vehicle, a pair of contact members within the housing and connectedin the alarm circuit, said contact members being spaced apart andmovable into contact with one another, one of said contact members beingsuspended for free swinging movement whereby a movement of the vehiclecauses the contact members to contact one another to complete the alarmcircuit, and an actuator shaft extending above and transversely of thetop of the elongated housing from which said suspended contact member issupported for a free swinging movement in said elongated housing, saidactuator shaft being adjustable laterally of the upper end of saidelongated housing to move said suspended contact member to a selectedelevation in said housing.
 5. An anti-theft detector for use on motorvehicles to actuate an alarm element in an alarm circuit, said detectorcomprising a housing swingingly supported from the vehicle so as tomaintain a vertical attitude independently of the inclination of thevehicle, a pair of contact members within the housing and connected inthe alarm circuit, said contact members being spaced apart and movableinto contact with one another, one of said contact members beingsuspended for free swinging movement whereby a movement of the vehiclecauses the contact members to contact one another to complete the alarmcircuit, and an actuator shaft extending above and transversely of thetop of the elongated housing from which said suspended contact member issupported for a free swinging movement in said elongated housing, saidactuator shaft being adjustable laterally of the upper end of saidelongated housing to move said suspended contact member to a selectedelevation in said housing, said suspended contact member being generallyspherical in shape and hAving a ring-shaped section around its center,the outer contact surface area of said ring-shaped section incliningoutwardly and downwardly and the inner associated contact surface areaof the other contact member inclining outwardly and upwardly to decreasethe air space therebetween as said suspended contact member is elevated.6. Anti-theft alarm apparatus for use on a motor vehicle to actuate analarm element comprising a detector on the vehicle having a set ofnormally open contact members adapted to momentarily close when thevehicle is moved, and an alarm circuit including means responsive to amomentary engagement of said contact members to actuate said alarmelement for a predetermined time interval each time said contact membersare closed, said vehicle having a DC battery and a horn, said hornserving as the alarm element and being actuated from said vehiclebattery, and a secondary alarm circuit triggered by the disconnecting ofsaid vehicle battery, said secondary alarm circuit including anauxiliary battery arranged for connecting the power from said auxiliarybattery to an audio generator having its output coupled to the input ofa radio broadcast receiver.